Glass containers are known that contain an infusion liquid which is fed to a patient through a hose system. Such containers are closed with a rubber-resilient stopper pierceable by the spike of a transfer device. The container is then suspended with its opening directed downward so that the liquid can flow out in a controlled manner through the withdrawing device. Air is allowed into the container through a venting channel of the penetrating spike so as to fill the volume cleared by the liquid and to avoid a vacuum in the container.
Such rigid containers are not suited for pressurized infusions where the infusion liquid is pressed from the container by applying external pressure. Pressurized infusions are applied to patients in a hypervolemic condition after loss of larger amounts of blood, e.g. after a traffic accident, in order to supply a large volume of liquid to the patient in a short span of time. Foil bags containing the infusion liquid are suited for such pressurized infusions. The foil bags contain no air and their volume adapts to the respective volume of the liquid. However, the manufacture of suitable foil bags is rather troublesome. As the material, multi-layered composite foils are used with at least one of the layers having special barrier properties.
More economic to manufacture are molded containers made and filled according to the blow-fill-seal method (BFS), wherein all process steps—blow molding the container, filling it and sealing it hermetically—occur in the molding tool.
Further known is a container of oval shape distributed by B. Braun Melsungen AG under the trade name Ecoflac plus® which is made in a BFS process and whose wall contracts when an infusion without additional venting is applied. However, the standing bottom and the shoulder portion of this container remain undeformed because of the stability imparted by the molding so that only the middle portion is constricted. This means that cavities will remain in the standing bottom and the shoulder portion even with the container collapsed. These cavities have to be filled with air to allow for a typical gravity infusion to be carried with this container. Such a gravity infusion requires that a volume of air is always present in the container. The required volume of air is rather large because of the dimensional stability of the end portions of the container mentioned. On the other hand, air has to be prevented from entering into the hose system of the transfer device since this would cause a risk of air embolism to the patient.
JP 2002 282 335 A describes an infusion container corresponding to the preamble of claim 1. The infusion container comprises a molded body that can be folded in an empty state prior to filling and after the withdrawal of the liquid. During the filling of the infusion liquid and during shipping after the filling, however, the container can stand upright. On two opposite side faces, the container has respective outer fold lines in the shape of an inverted Y and a transverse inner fold line connecting the outer fold lines. When folding the container bottom up, the outer fold lines deflect outward, whereas the inner fold line buckles. No folding occurs in the neck portion of the container. The container is deformed by manual action, the deforming behavior being influenced by the point at which the pressure is applied.
DE 37 27 972 A1 describes a liquid container in the form of a bag for receiving beverages such as orange juice and soft drinks. The bag is a side gusseted bag with a plurality of vertical welds. The bottom is made from flaps folded over each other. The bag can only stand unsupported when it is filled. It is not intended for suspending.
DE 699 03 510 T2 describes a generally cubic large bag for use in the biopharmaceutic industry which is designed as a bellows bag of welded foils. It is not a molded container. Further, the container neither has a neck portion nor a shoulder portion.
A side gusseted bag for medical purposes is described in DE 699 00 761 T2. The side gusseted bag is parallelepiped in shape when filled, the bottom being made of triangular flaps connected by sealing seams. Foil bags with numerous sealing seams require rather complex manufacturing.
DE 43 15 966 describes a foldable container made of an integral molded part and having longitudinal side gussets. The container is intended for manual compression so as to require less volume when it is disposed as waste.